Basment Toilet - New Construction

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MaximAvs

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SO I'm installing a bathroom in my basement and I'm at the portion of installing the toilet. We have a slab basement floor, and the builder (1980s) left about 9" of 3†ABS pipe sticking out of the concrete where the toilet should go. My question is on the flange. Please tell me if I’m wrong on any of the following, and suggest any steps I am missing.
I was going to cut the pipe off flush with the floor, and then get a plastic flange with a molded piece of female pipe in the center to be “glued†inside the pipe in the floor. My only concern with this is that these flanges have a lip on the bottom in the middle that will not allow the flange to sit flat on the floor. It’s up about 1/8†– 3/16†high. The other issue is if the flange cranks over time, There would be no way of replacing it without breaking up the concrete.

flangelz8.jpg


What sort of flange do I need and how does the one you suggest create a good seal AND be repairable and all this without having to bust up concrete? Thanks for any suggestions you have!!

Sean
 

Jadnashua

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Check carefully around the base of the pipe; if you are lucky, the builder put a sleeve around the pipe you can dig out to allow you to put a normal flange on the outside of the pipe. Note, it might be covered just at the top by a thin layer of cement.

It is considered 'ok' to use an internal flange on a 4" pipe (although outside is better), most do not like to do it on a 3" pipe.

The flange needs to sit flat on the floor, with no space underneath and you need to anchor the rim to the concrete, otherwise an inadvertent knock on the toilet after installation could break the flange. Plus, if it sits higher than that, some toilets won't fit - they'll be held up by the flange, rock, and break the wax seal in addition to the flange.

You might be able to use an internal cutter to get the top of the pipe slightly below the surface to then allow the flange to set down flush with the floor.
 

MaximAvs

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There is what looks like tar paper wrapped around the pipe now, but there would be no way that there would be enough space between it and the pipe to get an "outside" fitting.

On another note, should I be looking at a metal flange with an ABS fitting?!

Thanks for the help

Sean
 

Jadnashua

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Regardless of the materials of the flange, the ring must be anchored to the floor. There are numerous brands, each with slightly different construction details - one may allow it to fit in there flush with the floor. Again, an interior flange on a 3" pipe is to be discouraged.

Normally, there will be some covering on the floor - the flange should sit on top of the finished floor, not just the subfloor (or in this case the slab). So, if you were going to put down tile, you'd be raising the height enough to make room for the bevel on the flange. Vinal probably wouldn't be high enough, though.
 

Markts30

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For information sake for the other pros on the board....
This may not help you much as there is some cost involved - how much you could call around and find out - might not be too much...
I ran into a similar situation whil helping a buddy redo some plumbing and just core drilled a 5" hole around the pipe...
Chipping the "sleeve out was easy and took about 5 min...
Outside flange fit like a glove...
If you are going to do this, remember to plug the pipe with a test ball or rubber plug so the water for the core driller does not just run down the drain and make the diamond bit cut dry....
 

MaximAvs

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jadnashua...

Yes, I have already laid a vinyl sticky tile flooring down on the floor.

markts30...

I like your idea, but I'm not sure I want to do that with the room almost done.

I'd sure like a flange that had a metal ring and an ABS middle to bond to the inside of a 3" pipe. If that's not available I might be chipping concrete.
 

GrumpyPlumber

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Coring...I'd just get (rent) a rotary hammer with a flat bit...chisle the outside diameter and like Markst said..make ABSOLUTLEY sure you cover the drain....coring machines are messy, cumbersome.
I also probably prefer it because I keep a rotary on my truck.
 

MaximAvs

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So, the censensis is to chisel out the concrete around the drain?! Also an inside mount on a 3" drain is frowned upon?!

Thanks guys!

Sean
 

hj

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pipe

As soon as you said, "3 inch pipe", "encased in concrete", "insert flange", "ridge", you pretty much negated any hope of it ever being "easily repaired in the future".
 

GrumpyPlumber

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Seeing the pic I can honestly say I wouldn't even consider coring it wet...they do have dry bits though, but I stand by my original rotary hammer suggestion.
Also..Hard wood flooring isn't the greatest idea under a toilet.
It'll swell when wet and push the toilet up off the flange, slowly breaking the seal...can't be too good in the longterm on it's appearance either.
Even if you are able to get er'yone to "use their aim", bowls tend to sweat in warm or humid conditions.
 

MaximAvs

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GrumpyPlumber said:

Also..Hard wood flooring isn't the greatest idea under a toilet.
It'll swell when wet and push the toilet up off the flange, slowly breaking the seal...can't be too good in the longterm on it's appearance either.
Even if you are able to get er'yone to "use their aim", bowls tend to sweat in warm or humid conditions.

Actually it's not real hard wood! It's a vinyl floor that looks like hard wood! It comes in 4"x36" strips that you lay like a wood floor, but just stick to the concrete/subfloor. It carries through my basement into the lounge.
 

MaximAvs

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hj said:
As soon as you said, "3 inch pipe", "encased in concrete", "insert flange", "ridge", you pretty much negated any hope of it ever being "easily repaired in the future".

It's really looking that way!! Nothing has been easy with this project. I was really hoping that one thing would be easy.

Sean
 

GrumpyPlumber

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MaximAvs said:
Actually it's not real hard wood! It's a vinyl floor that looks like hard wood! It comes in 4"x36" strips that you lay like a wood floor, but just stick to the concrete/subfloor. It carries through my basement into the lounge.

well what'll they think of next?!?
At a glance it looks real...whats the stuff called?


(600th post!...soon I'll be at "Senile member" status!)
 

MaximAvs

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GrumpyPlumber said:
well what'll they think of next?!?
At a glance it looks real...whats the stuff called?

I forget the name of it off the top of my head (I'm at work), but I will take a picture of the box when I get home. I know I picked it up from Lowes over in the sticky vinyl tile area.
 

Cwhyu2

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I have an idea cultured marble slab .We used to put them under w/c on wood floors as per code.This will give 1/2 inch more to play with.So you do not
have chip out so much concrete.Also you will have room the under side of the flange.
 
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